$url = json_decode(file_get_contents("https://api.vk.com/method/photos.getMessagesUploadServer?access_token=".$this->token), true)["response"]["upload_url"];
$photo = __DIR__."/status1.jpg";
$post = ["photo" => curl_file_create($photo)];
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: multipart/form-data; charset=UTF-8'));
$result = json_decode(curl_exec($ch), true);
curl_close($ch);
В результате: пустой массив photo[]
